Our English teacher is always very       and makes us feel      .

I didn’t sleep ______last night.  I feel tired now. 

— Some of my classmates don’t like math because they think it’s boring.— I don’t like it, _____. I think it’s too difficult.

---Now the air in our hometown is even       than it was before. ---So we must do something to stop it.

—Do you think the first problem in this math test difficult?—Yes．I could        work it out．